US2833504A - Adjustable weight supporting mechanism - Google Patents

Description

May"6,j-1958 R. c. sAcKsTEDl-:R 2,833,504

ADJUSTABLE WEIGHT SUPPORTING MCHANISM 'Filed May 17. 1954 2 sheets-sheet 1 IZ i2 IN VEN TOR. Mcm/1w C'. Snc'ffsre'vsf?,

Hwy/Ma May 6, 1958 R. c. sAcKs'rEDER 2,833,504

` .ADJUSTABLE WEIGHT-SUPPORTING MECHANISM Filed May 17, 1954 Y 2 Sheets-Sheet 2 INVEN TOR. im CS Maxaman?,

Prof/V134 United; States Patent ADJUSTABLE WEIGHT SUPPORTING lVIECHANISM RichardtGvSacksteder; Elwood, Ind., assignor to General Lamps Manufacturing.; Corporation; Elwood, Ind., a.

corporation' of Indiana Application'v May-17, 1954, Serial No. 430,021'

4;(2laims.y (Cl: MSL-280) The present invention relates.` tov an adjustable weight ventionnds utility in supporting alamp, and it willbe described, -andhas beeny illustrated,in that-capacity,

though. it will-berccognized, of course, that the mechanism is adapted, as; well, to support any'other device which, in use may desirably-be positioned' in.Y any one ofv a, multiplicitylof relationships to thev foundation from whichfitzmay beultimately supported,

A primary objectof theinvention istoprovide a device.-

of.tle character describedwhich shallberelatively simple in construction, inexpensive. to manufacture, quite-free.`

fromniechanicab breakdown, easy 'pto move, and yet inherently stable in. any position of. adjustment within its.

range.

Further yobjects ofthe invention4 willV appearas the` description proceeds.

To the accomplishment of. the-above and. related ob-` jects, my inventionmay be embodiedin the, forms illustrated. in the accompanying drawings, attention being called to the fact,.however,.that.the drawings. are illustra- Y tive only and that change may be made inthe specific constructions'.illustrated and described, so long asy the scope of theappended' claims is not violated.

Fig.' l' is a side elevation of a preferred embodiment of". my invention, parts being broken away andparts being shown in. section for clarityA of illustration;

of`Fig'. 1, with parts broken away;

Fig. 3`is a'dia'gramm'ati'c illustration of. a rnodiiiedA form of'my invention; and

Ff. 4 is a Vsimilar.iilttstratioa ofa furthe; mediar-. 1l

formL thereof.'

Referringmore particularly" to the drawings, itwill beseen th'atl"l have illustrated'a lamp. 10 as` the load orweight to be supported by the adjustable mechanismk of my'invention. In its preferred embodiment,V .such

mechanism includes a base 1'1 provided with a pairof depending, threadedy stems 12, upon eachl of which" is sleeved a gripper 1'3 under the domination of a .wing nut 14 threaded'on the associated. stem 12, whereby the base. 60

may be clamped to a table top'or other support 15..`

As shown, a .trunnion l16 spans theopposite, upstanding,

walls of the base` 11 and provides ai pivotal. support for la carriage.1.7 upon whichuis .ixedly mountedan upstand.-

ing post 18. A` nut v19: is mounted, between the side wallsof the carriage 17, to oscillate. upon a pair of studs 20.; while a col-lar. 21 ismounted, upon: studs 22.carrie.d by the side walls of the basell, to oscillate upon a..

parallel axis... A screw 23 is journalled in thesleeve 21..'and, threadedly penetrates the` nut 19, said screw being held against axial movement relative to the. sleeve 2,1 by means of a pin 24 engaging the inner end of said Fig.' 2' is a fragmenta'l elevation,` viewed from the-right ice sleeve, and a knurled knob 2S engaging thev outer endof said sleeve.

Obviously, rotation of the screw 23 in one direction orthe other will swing the carriage 17, in one'dire'ction or the other, about the axis of` the trunnion 16 to adjustE the post 18 to al truly vertical position, in spite of any' slight departure of thesupport 15 from the horizontal.l

A bracket, indicatedy generally by the reference numeral 26, is formed to provide, at its lower end, a cylindrical portion- 27'bored to receive the post 18.` Preferably, a` bushing 28 is mounted inI the lower end of bracket:l portion 27 to provide a good bearing on the posty 181 As shown, the upper'end of the: post 18 is grooved, as'at 29, to receive a spring ring30 which holds the bracket 26" against .accidental removal from the post.

axis upon which, a lever 33' is mounted to swing. AS1 shown, the lever 33'is so supported uponthe trunnion.A

31'assto' have along, generally upwardly extending arm 34 and a short, generally downwardly extending arm At a level above the trunnion 31, the walls 32, 32 of the bracket are formed. with corresponding slots 36, 36,

each vofI which deiines a` generally horizontal, downwardly" An axle 37 carries` tworollers. 3S, 3S which rollers are received in the respective slots.

facing retaining surface:

36, 36 and engage the said downwardly facing surfaces. A rocker element, which comprises the two pieces 39,

39, is pivotally mounted uponthe axle 37 which, withtits rollers 38, 38 comprises a fulcrum meanswhich is mounted for transaxial movement. in the guideway'36,4 36; and

it will be seen that the path of movement of said fulcrumf means is olset both vertically and horizontally from the` pivotal axisdened by the trunnion 31.

A link 40 has one end pivoted at 41 upon that end of therocker element` 39 nearer the trunnion 31; and a-- second. link 42 has one end pivotally connected, at 43, tovi that endof the rocker element 39 more remote from theyr trunnion 31. In the illustrated.embodimentofthe invention, thepivotal connections 41 and. 43 are. about equi:- distant from the axle 37.

A secondrocker element 44 ispivotally connected at- 45 tothe other end of link 40, andis pivotally connected l at 46 to the other end of link 42. The pivotal connections 45 and 46 are spacedV apart a distance equal to the disj tance between the pivotal connections 41 and `43, so that' the rocker elements. 39 and 4.4 and. thelink elements 40 and, 42 cooperate to define av parallelogram.

The remote end of the long leverl arm34 isspivotally.

connected at 47 to the link 42 at a point near the pivotal...y

connection 43.

An arm 48 is suitably supported l,in the rocker-element 44, and .carries the lamp 16 (or other, loadto be supported) at its outer end.

A member which,v in the illustrated embodiment of the invention, comprises a hollow rod'49, is ypivoted at 56 to the short arm 3S of the lever 33. The remote end ofthe rod`49f is threaded, as at .51, for the recep.-

tionlofa nut 52 which adjustably engages and supports.

a seat 53.' At a point between thethreadedr endv olf.V the, rod y49 and the vertical plane including the axis of` the. trunnion 31the walls 32 of the bracket, 26. support a pair of aligned studs 54 against which bearsean, abutment ring55` sleeved on the. rod 49 and supporting-la.

seat 56.. A coiled. spring 57 is confined between thel seats.53. and-56.rand. resilientl-y resists clockwise movement of ...the lever 34.

Whenwthe above-described parts are proportioned and. i

arranged according to the relation dened hereinbelow,

It will be= f seen that the bracket 26 is thus mounted for rotation-1 a vertically-upward component which exactly counterbalances the downward componentof the force exerted upon the same pointfrom `the supported load, and the system will be in equilibrium. y

` Though all pivot points are designed and `arranged to permit relatively free movement of the parts thereabout, "there `is sufficient friction in the `system to compensate for slight variations from mathematically exact equilibrium. However, the system isso designed that the following relations between the parts are maintained:

(1)7The length of the lever arm between points 43 and 47 multiplied by the product of the lever arm between points 31 and 50 rand the distance between 31 and 54 and by the spring constant in pounds per inch is equal to the lever Varm between points 47 and 31 multiplied by the moment of the system about point 37 where the angle between thevertical and theline `joining points 37 and 43 is 180 and the angle between the verticaland the line joining the points 43 and 47 is 90.

(2) The lever arm from 37 to 43 multiplied by the productoflthe lever arm from 31 to 50, and the distance between 31 and 54 and by the spring constant isequal to the lever arm from 31 to 47 multiplied by the moment of the system about point 37 if the angle included between the vertical and a line joining points 37 `and 43 is 90 `and the line joining points 43 and 47 is vertical. t

t (El)` The system should be designed in such a way that the angle between the line connecting 47 and 31 and the verticallis equal to the anglebetween the linev 50-31 and the line 31-54.

, It will be Yobvious that a number of variations in `thespecifc linkage as illustrated in Figs. -1 and 2 are possible, within the scope of the invention; and I have illustrated, more or less diagrammatically, two such variations. Thus, in Fig.3, the bracket 26' supports a trunnion 31,' upon which is swingably mounted a. lever corresponding to the lever 33 and comprising a long, generally upwardly extending arm 34 and a short, generally downwardly extending arm 35'. The bracket 26 is formedwith guideways 36in which a fulcrum 37 is transaxially guided for substantially horizontal movement.` An extension; 40" of the link 40' lis pivotally mounted upon the'fulcrum 37. ally connected at 41 to that end of the rocker member 39 closer to the trunnion 31. A link 42 is pivotally connected at 43 to the opposite end of the rocker 39'; and the remote ends of the links 40 and 42 are pivotally connected, at 45' and 46', to au upper rocker 44 upon which is carried the arm 48 which supports the load 10. r

` A rod 49' is Ipivotally'connected at 50 to the lever arm 35', and a `springj57' cooperates with the rod 49 precisely in the manner in which the spring S7 cooperates with the rod 49, being confined between a seat 53' fixed to said rod and a seat 55 bearing against the stops 54.

In `the modification `illustrated in Fig. 4, the bracket 26a is shaped somewhat diferently from the bracket 26; but it supports a trunnion 31a upon which is journalled a lever having a long, generally downwardly pro-` iecting arm 34a and a short, generally upwardly proiecting arm 35a. The bracket 26a provides a guideway 36a in `which a fulcrum 37a is ,guided for transaxial, generally horizontal movement.

A rocker `39a is pivotally mounted upon the extremity of thelever arm 34a, as at 47a; and links 40a and 42a are pivotally connected, as at 41a and 43a, to the opposite ends of the rocker 39a.` The upper ends of the links 40a and 42a arepivotally connected, as at 45a and 46a, to an upper rocker 44a which supports the arm 48 upon which is carried the load 10. In this form of the invention, the 'z link 42a is pivotally supported,

Said link 40 is pivot-A 4 at a point near the pivotal connection 43a, from the fulcrum 37a.

A rod 49a is pivotally connected at 60 to a portion 61 of the bracket 26a, and a coiled spring 57a is sleeved on said rod, being confined between the abutment element 53a which is fixed to the rod 49a and the abutment element 55a which is slidably sleeved on the rod, and to which the lever `arm 35a is pivotally connected, as at 62.

I claim as my invention:

1. A mechanism of the class described, comprising means providing a fixed, generally horizontal pivotal axis, a lever mounted to swing about said axis, means providing a generally horizontal guideway spaced from said axis and extending transversely with respect thereto, fulcrum means providing an axis substantially parallel with said pivotal axis and guided for trans-axial movement along said guideway, said fulcrum means being horizontally offset from said pivotal axis, four elements defining a parallelogram and comprising a rst rocker element, a second rocker element in parallel, spaced relation `to said first rocker element, a first link element pivotally connected to said first rocker element and to saidsecond rocker element, and a second link element in parallel, spaced relation to said first link element and pivotally connected to said first rocker element and to said second rocker element, one of said four elements being pivotally supported from said fulcrum means, means providing a pivotal connection between said lever and another of said four elements adjacent said one element, means for supporting a load from a third one of said four elements, and means operatively engaging said lever and yieldably resisting movement of said lever under the influence of gravity upon such a load.

2. A mechanism of the class described, comprising means providing a fixed, generally horizontal pivotal axis, a lever mounted to swing about said axis, means providing a generally horizontal guideway spaced from said axis and extending transversely with respect thereto, fulcrum'means providing an axis substantiaHy parallel with said pivotal axis and guided for transaxial movement along said guideway, said fulcrum means being horizontally offset from said pivotal axis, four elements defining a parallelogram and comprising a lower rocker element, an upper rocker element in parallel, spaced relation to said lower rocker element, an inner link element pivotally connected to said lower rocker element and to said upper rocker element, an outer link element in parallel, spaced relation to said inner link element and pivotally connected to said lower rocket element and to said upper rocker element at points respectively more remote from said pivotal axis than the points of connection of said inner link element to said` rocker `elements, said lower rocker element being pivotally supported from said fulcrum means, means providing a pivotal connection between said lever and said outer link element, means for supporting a load from said upper rocker element, and means operatively connected to said lever and yieldably resisting movement of said lever under the influence of gravity upon such a load.

Y3. A mechanism of the class described, comprising means providing a fixed, generally horizontal pivotal axis, a lever mounted to swing about said axis, means providing a generally horizontal guideway spaced from said axis and extending transversely with respect thereto, fulcrum means providing an axis substantially parallel with said pivotal axis and guided for'transaxial movement alongv said guidewaysaid fulcrum means being offset from said pivotal axis, four elements defining a parallelogram and comprising two parallel, verticallyseparated elements and two parallel, horizontally-separated elements, each of said horizontally-separated elements being pivotally connected to both of said verticallyseparated elements, one of said four elements being pivaseaeoe otally connected to said fulcrum means, means providing a pivotal connection between said lever and another of said four elements adjacent said one element, means for supporting a load from a third of said four elements, a member pivotally connected to said lever, abutment means carried by said member at a point remote from the point of connection of said member to said lever, abutment means fixed with respect to said pivotal axis and disposed between said point of connection and said rst-named abutment means, and a coiled spring sleeved on said member and confined between said abutment means.

4. A mechanism of the class described, comprising means providing a txed, generally horizontal pivotal axis, a lever pivotally supported intermediate its ends upon said means to swing about said axis and having a long arm and a short arm, means providing a generally horizontal guideway spaced from said axis and extending transversely with respect thereto, fulcnlm means providing an axisA substantially parallel with said pivotal axis and guided for transaxial movement along ysaid guideway, said fulcrum means being vertically'oEset from said pivotal axis, four elements defining a parallelogram and comprising two parallel, vertically-separated elements and two parallel, horizontally-separated elements, each of said horizontally-separated elements being pivotally connected to both of said vertically-separated elements, one of said four elements being pivotally connected to said fulcrum means, means providing a pivotal connection between the long arm of said lever and another of sa-id four elements adjacent said one element, means for supporting a load from a third of said 'four elements, a member pivotally connected to the short arm of said lever and projecting therefrom at an angle to a line joining said pivotal axis with the point of connection of saidv member to said lever, abutment means carried by said member at a point remote from said point of connection, abutment means iixed with respect to said pivotal axis and disposed between said point of connection and said rst-named abutment means, and a coiled spring sleeved on said member and confined between said abutment means.

References Cited in the le of this patent UNITED STATES PATENTS Re. 12,674 Marten July 23,1907 2,076,446 Carwardine Apr. 16, 1937 2,200,518 Perbal May 14, 1940 2,547,532 Mendelsohn f Apr. 3, 1951

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